In Problems 13.85 through 13.89 on page 568, you constructed simple linear regression models to investigate the relationship between demographic information and monthly sales for a chain of sporting goods stores using the data in Sporting. Develop the most appropriate multiple regression model to predict a store's monthly sales. Be sure to include a thorough residual analysis. In addition, provide a detailed explanation of the results, including a comparison of the most appropriate multiple regression model to the best simple linear regression model.